Rotor assembly for an axial turbine

ABSTRACT

A rotor assembly includes a drive shaft; a rotor having rotor blades, which each comprise a profiled rotor blade section and a blade fastening section; wherein each blade fastening section comprises a first contact region and a second contact region, the first contact region being at least indirectly supported on the blade fastening section of a first adjacent rotor blade, the second contact region being at least indirectly supported on the blade fastening section of a second adjacent rotor blade; the blade fastening sections are fastened in a formfitting manner and/or by a screw connection on the drive shaft, so that there is a connection between rotor blade and drive shaft on an axial end face of the blade fastening section. Intermediate elements having an elastic intermediate layer are between the blade fastening sections of adjacent rotor blades.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of PCT application No. PCT/EP2012/001019,entitled “ROTOR ARRANGEMENT FOR AN AXIAL TURBINE AND A METHOD FORMOUNTING SAME”, filed Mar. 8, 2012, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a rotor assembly for an axial turbine, inparticular having a propeller-shaped rotor for a tidal power plant or awind power plant having horizontal axis of rotation.

Tidal power plants having a horizontally aligned drive shaft, whichrevolves on a nacelle, and which is driven by a propeller-shapedturbine, are known and correspond to the design of wind power plants inhorizontal rotor construction. For tidal power plants, the rotors ofaxial turbines of this type are either implemented as units having freeflow around them or are encased by a jacket housing having Venturigeometry for flow acceleration. The rotor assembly described hereaftermay also be transferred to further axial fluid-flow machines, such asfans.

For efficient energy utilization of slow currents in bodies of water,such as continuous ocean currents or tidal currents, large-scale rotorsare required. Corresponding requirements result in the field of windpower, in particular for offshore plants. High forces and torques resulttherefrom on the region of the rotor blade attachment at the hub, whichis in rotationally-fixed connection to the drive shaft. Correspondingly,the highly loaded components for the rotor blade attachment must bedesigned with a sufficient safety reserve for tidal power plants, sincethe cyclic variations of the tidal current caused by the phase of themoon are strongly overlaid by weather influences. Thus, depending on thewaves, the wind direction, and the existing topography on the floor ofthe body of water for the respective plant location, meteorologicallyinfluenced currents occur, which result in a fluctuating load on therotor.

Furthermore, a simplified plant concept having rigidly linked rotorblades is preferable for tidal power plants because of the accessibilityfor maintenance work, which is more difficult. In many cases, a devicefor rotating the plant around a vertical axis is additionally omittedand instead a rotor having rotor blades which can have bidirectionalincident flow is used. This has the result that upon the occurrence ofthe overload, the rotor blades cannot be transferred by means of a pitchangle adjustment into the vane position, as is typically the case in thedesign used for wind power plants. The entire plant also cannot berotated out of the current. Accordingly, a high standard results for thestructural stability of the rotor blade attachment for tidal powerplants, which results in heavy, large-scale, and expensive fasteningcomponents.

The heretofore known rotor design for axial turbines of tidal powerplants is directed to a modularly constructed rotor, for which theindividual rotor blades are installable separately on a hub. For thispurpose, the hub has receptacles for blade fastening sections of therotor blades. Such blade fastening sections are typically appliedcylindrically, wherein a transition region to the profiled rotor bladesections, which interact with the current field, having higherstructural stability is provided. For this purpose, reference is made,for example, to WO 2010/125478 A1. The cylindrical blade fasteningsections typically have a diameter which is less than the chord lengthof the directly adjoining profiled rotor blade sections and is greaterthan the profile thickness in this region. There is thus a constriction,from which a notch effect results in the event of a load of the rotorblades, which must be secured by additional structural reinforcements.

Furthermore, the known blade fastening sections typically have on thehub-side end a fastening flange, which is used to form a screwconnection between the blade fastening section of the rotor blade andthe hub part of the revolving unit adjoining thereon. Such a rotor bladefastening is disclosed for wind power plants by U.S. Pat. No. 6,305,905B1, for example. Corresponding fastening flanges for rotor blades on ahub of a tidal power plant result from GB 2467226 A, wherein aflange-shaped blade fastening section, which is formed in one piece withthe profiled rotor blade section, is covered by means of a fasteningring for securing on the hub part. Reference is made to U.S. Pat. No.5,173,023 and GB 502409 for further rotor blade attachments.

SUMMARY OF THE INVENTION

The present invention is based on the object of specifying a rotorassembly for an axial turbine having a plurality of individuallyinstallable rotor blades, which is distinguished by a high structuralstability of the rotor blade fastenings and by an efficient force andtorque transmission to an adjoining drive shaft. In addition, a rotorblade design is desired, which allows simple replacement of individualrotor blades. Furthermore, the rotor assembly is to be used inparticular for operating a tidal power plant and is preferably to besuitable for implementing an axial turbine which can have bidirectionalincident flow. The rotor arrangement must be able to absorb inparticular asymmetrical load peaks which only act on individual rotorblades and must be simplified both in design and manufacturing.Furthermore, an installation method for such a rotor blade assembly issought.

The present invention is achieved by the following features: a rotorassembly, comprising: a driveshaft having an assigned axis of rotation,which establishes an axial direction and a circumferential direction; arotor having a plurality of rotor blades, which each comprise a profiledrotor blade section, which can have incident flow in the axialdirection, and a blade fastening section; wherein each blade fasteningsection comprises a first contact region and a second contact region andthe first contact region is at least indirectly supported on the bladefastening section of a first adjacent rotor blade and the second contactregion is at least indirectly supported on the blade fastening sectionof a second adjacent rotor blade; the blade fastening sections arefastened in a formfitting manner and/or by means of a screw connectionon the driveshaft, so that there is a connection between rotor blade anddrive shaft on an axial end face of the blade fastening section, whichis opposite to an axial terminus face on the driveshaft in the installedposition; and for each rotor blade, the transition from the profiledrotor blade section to the blade fastening section has an externalcontour which is free of constrictions; the invention is characterizedin that intermediate elements having an elastic intermediate layer areprovided between the blade fastening sections of adjacent rotor blades.

The inventors have recognized that instead of fastening individual rotorblades to a hub, the carrying capacity of a rotor blade mount increasesby omitting an integral hub component. According to the invention,individual hub segments are assigned to the replaceable rotor blades.These hub segments form blade fastening sections, which mutually supportone another at least in the circumferential direction and at leastindirectly.

Preferably, for rotors which can have bidirectional incident flow, notonly pressure forces in the circumferential direction between the bladefastening sections are mediated, but rather additionally traction forcesin the circumferential direction and axial force components are absorbedby a detachable connection of adjacent blade fastening sections. A screwconnection and/or a formfitting connection preferably comes intoconsideration as the detachable connection, so that in the event ofplant maintenance, individual rotor blades can be separately adjusted orreplaced. For an advantageous embodiment, the blade fastening sectionsform a segmented hub part after the execution of the installation on thedrive shaft due to the interaction with the respective adjacent bladefastening sections.

Each rotor blade of the rotor blade assembly according to the inventioncomprises a profiled blade section and a blade fastening section, whichis preferably materially joined thereto, and which is supported onand/or detachably connected to a corresponding blade fastening sectionof an adjacent rotor. The profiled rotor section of the rotor bladesrepresents the part of the rotor blade which interacts with the currentfield in a usable manner. In the event of a drive by a current in a bodyof water, the profiled rotor blade section is accordingly thehydrodynamically active part of the rotor blade having an adapted bladeprofile. In the case of a rotor which can have bidirectional incidentflow for a tidal power plant, symmetrical profiles are used for thispurpose, wherein an elliptical geometry can be provided for adouble-axis symmetrical profile, for example. Alternatively,point-symmetrical profiles having a profile bulge, i.e., reflexedtrailing edge profiles, can be used.

Each rotor blade particularly preferably has a one-piece embodiment ofthe assigned profiled rotor blade section and the assigned bladefastening section. The rotor blade can be produced from GFRP (glassfiber reinforced plastic) or CFRP (carbon fiber reinforced plastic)material or from steel, wherein contact regions on the blade fasteningsections, which are used for force transmission to blade fasteningsections of an adjacent rotor blade, are preferably reinforced byembedding abrasion-resistant materials, for example, a coupling elementmade of metal. For a further advantageous design, the blade fasteningsections are produced as cast parts. Profiled rotor blade sections whichare manufactured from steel, CFRP, or GFRP are materially joinedthereon.

For an alternative embodiment, blade stubs, which form a first part ofthe profiled rotor blade section, are materially joined on the bladefastening section, wherein a second part of the profiled rotor bladesection is detachably connected to the blade stub. The transition fromthe first part to the second part of the profiled rotor blade sectioncan be embodied as an intended breakpoint to secure the entire plantfrom severe destruction in case of overload. Furthermore, thepossibility exists of providing this transition region with anelasticity to implement a bending-rotating coupling of the rotor blade.

The blade fastening sections are fastened in a formfitting manner and/orby means of a screw connection to a drive shaft of the rotor assembly,so that each individual rotor blade is connected in a rotationally-fixedmanner to the drive shaft. This connection can be conveyed through oneor more of the intermediate elements, so that the rotationally-fixedlinkage of the rotor blades is at least indirectly provided. For therotor blade assembly embodied according to the invention, only a part ofthe forces and torques introduced from the profiled rotor blade sectionsare transmitted to the respective connection of the rotor blades to thedrive shaft, since a further part of the force action is absorbed by themutual support of the adjacent blade fastening sections.

For a preferred embodiment, the connection between rotor blade and driveshaft is implemented on an axial end face of the blade fasteningsection, which in the installation position is opposite to an axialterminus face on the drive shaft. Due to the incident flow on a rotorblade, in particular shear loads arise in the axial direction, whichresult in force components in the circumferential direction on thecontact regions of adjacent blade fastening sections. For this reason,for an advantageous embodiment of the invention, each blade fasteningsection comprises a first contact region and a second contact region aswell as the above-described third contact region to the drive shaft. Thefirst contact region and the second contact region are preferablyspatially partitioned. The first contact region and the second contactregion alternatively adjoin one another and merge into one another.

The first and the second contact regions are established by respectiveinteraction with the directly adjacent rotor blade. For a firstembodiment, the first contact region is at least indirectly supported onthe blade fastening section of a first, directly adjacent rotor bladeand the second contact region is accordingly at least indirectlysupported on the blade fastening section of a second, directly adjacentrotor blade. A rotor, having axial flow from an axial direction, of anaxial turbine can thus be implemented in leeward operation. For a rotorwhich can have bidirectional incident flow, which is capable of bothleeward and also windward operation, the first contact region and thesecond contact region preferably have means for the detachableconnection to the respective adjoining blade fastening section of theadjacent rotor blade. These means can be implemented in the form of ascrew connection and/or as a formfitting connection.

The contact regions are particularly preferably displaced into theintermediate blade regions, which are less mechanically loaded. Theseintermediate blade regions are thus defined in that their angular offsetin the circumferential direction to a partition plane between adjacentrotor blades is at most ±30° and preferably at most ±15°. The partitionplane extends centrally between adjacent rotor planes, which areassigned to individual rotor blades and are respectively spanned by theaxis of rotation of the drive shaft and a further straight line, whichis characteristic for the transition from the profiled rotor bladesection to the blade fastening section. In the simplest case, a rotorblade having a radial beam geometry is provided, i.e., the threadinglines of the profiled rotor blade sections follow a straight line in theradial direction. For this case, a rotor plane is established by thethreading line and the axis of rotation.

However, the case can occur that the profiled rotor blade sectionsextend in a sickle shape. An embodiment is thus conceivable for whichthe profiled rotor blade sections do extend in the rotor plane which isdefined as axially-symmetrical to the axis of rotation, but thethreading lines do not follow straight lines. Furthermore, it isconceivable that the profiled rotor blade sections are curved such thatthey leave the rotor plane. For such space-occupying applied profiledrotor blade sections, a characteristic point, for example, the point onthe chord line at half profile depth, is selected to establish the rotorplane on a predetermined profile section in the transition from theblade fastening section to the profiled rotor blade section. A straightline extending through this point in the radial direction and also theaxis of rotation then define the rotor plane.

In the case of a rotor having more than three rotor blades, theintermediate blade regions are preferably in an angular interval of40-60% of the angle which is formed by a section of the rotor planehaving rotor planes located adjacent to one another. For a rotor onwhich substantially higher shear forces than torsion forces act, theintermediate blade regions are less loaded in relation to the remainingregions of the blade fastening sections. The connecting elements for theblade fastening sections of adjacent rotor blades advantageously lie inthis region. These can represent components which interlock in aformfitting manner, for example, and which are fastenable to one anotherby a relative movement in the axial direction of the rotor.

According to an advantageous embodiment, an elastic intermediate layeris provided between adjoining blade fastening sections, in particularthe contact regions facing toward one another. Elastomeric materialshaving a high carrying capacity, which are typically used to implementseawater-proof plain bearings, come into consideration for this purpose.These materials are typically loadable with pressure and have a highabrasion resistance for a hard/soft pair. A certain relative movement ofadjacent rotor blades, which arises because of impact loads, can becompensated for by the elastic intermediate layer.

For a refinement, it is conceivable to mediate the detachable connectionbetween the blade fastening sections of adjacent rotor blades by way ofadditional intermediate elements. In contrast to the known hubcomponents, however, these do not form an integral structure, but ratherare implemented as separate components which are arranged spatiallypartitioned. For a refinement of the invention, these intermediateelements are capable of adapting the installation location of the rotorblades to the respective site. This allows the use of standardized rotorblades and a change of the rotor blade geometry, in particular the angleof attack of the profiled rotor blade sections, by a correspondingselection of the intermediate elements.

An embodiment is particularly preferred, for which the entirety of theblade fastening sections of the rotor in the fastened state encloses acentral free region, which is used to accommodate a shaft part of adriveshaft adjoining the rotor. The contour of the central free regionis particularly preferably designed such that it deviates from thecircular contour and transmits the drive torque generated from the rotorthrough a form fit with a corresponding complementarily implementedshaft connecting part.

In addition to the displacement of the connecting elements into the lessloaded intermediate blade regions, the design according to the inventionallows the reduction of the notch effect in the transition from theprofiled rotor blade sections to the blade fastening sections. This isachieved because the heretofore typical cylindrical design of the bladefastening sections for accommodation in a recess on a hub part isreplaced by the assignment of a hub segment to an individual rotorblade. Large-scale blade fastening sections result therefrom, withoutthe segmented hub part, which arises due to the joining together of therotor blades, experiencing a size growth.

To reduce the notch effect, there are preferably no constrictions in theregion of a radial section of the rotor blade which establishes atransition region between the profiled rotor blade sections and theblade fastening section. A transition region which results in acontinuous tapering of the rotor blade above a limiting radius in thedirection radially outward is particularly preferred. An alternativeembodiment is also conceivable, for which the profile regions which areessential for structural stability, i.e., the profile lugs, protrudesomewhat beyond the transverse extension of the blade fastening sectionon the profiled rotor blade section. The profile chord in thisattachment region can exceed the transverse extension of the bladefastening section by up to 20%, without a substantial growth of thenotch effect resulting.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 shows a perspective view of a first exemplary embodiment for arotor assembly according to the invention in the partially-installedstate;

FIG. 2 shows a second exemplary embodiment for a rotor assemblyaccording to the invention in the partially-installed state in aperspective view;

FIG. 3 shows an alternative rotor design in an axial horizontalprojection;

FIG. 4 shows a detail from FIG. 3 in an enlarged view;

FIG. 5 shows a rotor assembly according to the invention having a rotoraccording to FIG. 3 in the installed state on the driveshaft; and

FIG. 6 shows a further, alternative rotor design in an axial horizontalprojection.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate embodiments of the invention, and such exemplifications arenot to be construed as limiting the scope of the invention in anymanner.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a schematic simplified view of a rotor assembly accordingto the invention having a driveshaft 1 and a rotor 20 having three rotorblades 2.1, 2.2, 2.3. The driveshaft 1 comprises an axis of rotation 21,which establishes an axial direction 22 and a circumferential direction23. Each rotor blade 2.1, 2.2, 2.3 comprises a profiled rotor bladesection 3.1, 3.2, 3.3 for interacting with the current field and a bladefastening section 4.1, 4.2, 4.3. The blade fastening sections 4.1, 4.2,4.3 are connected in a rotationally-fixed manner to the driveshaft 1.The boreholes 17.1, . . . , 17.n on a first axial end face 24 are usedfor this purpose, which correspond with threaded boreholes 27.1, . . . ,27.n on the axial terminus face 26 of the driveshaft 1.

For the rotor blade 2.1, the profiled rotor blade section 3.1 ismaterially joined to the assigned blade fastening section 4.1 for theillustrated, preferred design. The further rotor blades 2.2, 2.3 areaccordingly designed such that there is a material bond between therespective profiled rotor blade section 3.2, 3.3 and the assigned bladefastening section 4.2, 4.3. The rotor blades 2.1, 2.2, 2.3 can beproduced from different construction materials. In addition to castparts, steel and fiber composite materials based on GFRP and CFRP comeinto consideration for this purpose. Connecting different materials toimplement the rotor blades 2.1, 2.2, 2.3 is also conceivable.

Each blade fastening section 4.1, 4.2, 4.3 comprises a first axial endface 24 and a second axial end face 25, which are formed by plate-shapedelements spaced apart from one another. The plate-shaped elements areconnected by a terminus plate, which extends in the installed state inan axial sectional plane of the driveshaft 21, at a first contact region7.1, 7.2, 7.3 and at a second contact region 8.1, 8.2, 8.3, so that alight-construction but torsion-resistant structure results, which offerseasy accessibility for installation work through the side openings 32 inthe box-shaped structure.

In the installed state, the first contact region 7.1, 7.2, 7.3 for afirst rotor blade 2.1, 2.2, 2.3 is opposite to the second contact region8.1, 8.2, 8.3 on the blade fastening section 4.1, 4.2, 4.3 of arespective directly adjacent rotor blade 2.1, 2.2, 2.3. The firstcontact regions 7.1, 7.2, 7.3 and the second contact regions 8.1, 8.2,8.3, which face toward one another in the installed state, are used forthe mutual support of the blade fastening sections 4.1, 4.2, 4.3 in thecircumferential direction 23.

For the incident flow direction 28 shown in FIG. 1, the rotor 20 is onthe leeward side. As a consequence, the resulting shear forces 30.1,30.2, 30.3 on the profiled rotor blade sections 3.1, 3.2, 3.3 result, inthe blade fastening sections 4.1, 4.2, 4.3, in the outlined forcecomponents 29.1, 29.2 in the circumferential direction 23, which areabsorbed by mutual contact of the blade fastening sections 4.1 and 4.3.

FIG. 2 shows a refinement of the invention for a rotor assembly whichcan have bidirectional incident flow, wherein fastening means areprovided on the first contact regions 7.1, 7.2, 7.3 and the secondcontact regions 8.1, 8.2, 8.3, in order to absorb the alternatingcompression and traction forces outlined by the force components 29.3,29.4. Dovetail-shaped fastening elements 10.1, . . . , 10.5 are shown asan example for this purpose, which allow joining together of the bladefastening sections 4.1, 4.2, 4.3 by way of an axial movement of therespective rotor blade 2.1, 2.2, 2.3 relative to the already installedcomponents. Threaded bolts are used as an additional, detachableconnection of the blade fastening sections 4.1, 4.2, 4.3—the fasteningelement 6 is shown as an example for this purpose in FIG. 2.

A further embodiment is shown in FIG. 3. This shows a horizontalprojection of the first axial end face 24 of the blade fasteningsections 4.1, 4.2, 4.3 having boreholes 17.1-17.n for fastening on adriveshaft 1, which is outlined in FIG. 5. FIG. 4 shows the secondcontact region 8.2 on the blade fastening section 4.2 and the firstcontact region 7.3 on the blade fastening section 4.3 in an enlargedillustration as a section in the plane established by the longitudinalaxes 9.1, 9.2, 9.3 of the profiled rotor blade sections 3.1, 3.2, 3.3.The contact regions 8.2, 7.3 are detachably connected by threaded bolts11.1, 11.2, which enclose and pre-tension an elastic intermediateelement 13. An elastic plain bearing material is suitable for thispurpose, for example, the elastomeric material Orkot®. The elasticintermediate element 13 allows a certain mobility of the rotor blades2.1, 2.2, 2.3 in case of an asymmetrical load.

Furthermore, it is apparent from FIG. 4 that for the illustratedpreferred embodiment, a lateral opening 31 is provided in the box-shapedblade fastening sections 4.2, 4.3, which reduces the weight of the rotorblade attachment and allows the accessibility to the boreholes17.1-17.n, which are used for the shaft attachment, for theinstallation.

Furthermore, FIG. 4 shows that the mutual support points of the bladefastening sections 4.1, 4.2, 4.3 are applied in an intermediate bladeregion 18.1, 18.2, 18.3 between the force introduction regions at thetransition to the profiled rotor blade sections 3.1, 3.2, 3.3. Forclarification, a partition plane 32 is outlined between the secondcontact region 8.2 of the blade fastening section 4.1 and the firstcontact region 7.2 of the blade fastening section 4.2, which partitionplane is at half of the angle between the longitudinal axes 9.1 and 9.2of the profiled rotor blade sections 3.1, 3.2, which establish the rotorplanes for the rotor blades 2.1, 2.2 in conjunction with the surfacenormals to the plane of the drawing (axial direction). Those regionswhich are more weakly loaded in relation to the remaining parts of theblade fastening sections 4.1, 4.2, 4.3 during operation of the rotor 20lie within an intermediate blade region 18.1, 18.2, 18.3 established bya maximum angular offset of ±15°.

A further structural reinforcement results from an advantageous designof the transition regions 19.1, 19.2, 19.3 between the profiled rotorblade sections 3.1, 3.2, 3.3 and the blade fastening sections 4.1, 4.2,4.3. The advantageous embodiment according to FIG. 3 shows an externalcontour which is free of constrictions, so that the notch effect at therotor blade attachments is reduced. A continuous tapering from the bladefastening section to the profiled rotor blade section 3.1, 3.2, 3.3toward the radial outside is particularly preferably provided from aspecific radius.

In the installed state, the blade fastening sections 4.1, 4.2, 4.3 ofthe rotor blades 2.1, 2.2, 2.3, which are detachably connected to oneanother, form a segmented hub part 5, which has a central free region 14for an advantageous embodiment. For the embodiment shown in FIG. 3, thecentral free region 14 is triangular in relation to a section in therotor plane. Such a central free region 14 of the segmented hub part 5which deviates from the circular shape allows, after all rotor blades2.1, 2.2, 2.3 of the rotor 20 have been successively installed, therotor blades to be pushed onto a complementary shaft connecting part 16of a driveshaft 1, with which a form fit is produced. This is shown inFIG. 5 as a horizontal projection of the second axial end face 25 of therotor 20. The concealed, first axial end face 24 having the boreholes17.1, . . . , 17.n (not visible in FIG. 5) is pressed against the axialterminus face 26 of the driveshaft 1 for fastening. A rotor 20 installedin this manner can be partially installed for maintenance purposes, inthat individual rotor blades 2.1, 2.2, 2.3 are separately replaced orreadjusted with respect to the relative location to the further rotorcomponents or to the driveshaft 1. For this purpose, it is conceivablethat the boreholes 17.1, . . . , 17.n permit a certain installationfreedom by way of the use of oblong holes. For a refinement (not shownin detail), a securing element which is detachably connected to thedriveshaft 1 adjoins the shaft connecting part 16, which securingelement overlaps and axially secures the second axial end face 25 of theblade fastening sections 4.1, 4.2, 4.3 in the installed position.

For the exemplary embodiment shown in FIG. 6, intermediate elements13.1, 13.2, 13.3 are used to implement the detachable connection of theblade fastening sections 4.1, 4.2, 4.3. These represent separatecomponents which are arranged spatially partitioned and are used tocouple the rotor blades 2.1, 2.2, 2.3. For a refinement (not shown inthe figures), the intermediate elements 13.1, 13.2, 13.3 can have a formfit with the shaft connecting part 16 of the driveshaft 1.

In addition, an embodiment is conceivable for which intermediateelements 13.1, 13.2, 13.3 which are adapted specifically for the plantare used, which implement a tilted setting of the rotor blades 2.1, 2.2,2.3. The irregularities resulting for this case on the end face of therotor 20, which faces toward the adjoining driveshaft 1, must besupported with appropriately adapted wedge elements for secure contact.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

LIST OF REFERENCE NUMERALS

1 driveshaft

2.1, 2.2, 2.3 rotor blade

3.1, 3.2, 3.3 profiled rotor blade section

4.1, 4.2, 4.3 blade fastening section

5 segmented hub part

6 fastening element

7.1, 7.2, 7.3 first contact region

8.1, 8.2, 8.3 second contact region

9.1, 9.2, 9.3 longitudinal axis

10.1, . . . , 10.6 formfitting fastening element

11.1, 11.2 threaded bolts

12.1, 12.2, 12.3 elastic intermediate layer

13.1, 13.2, 13.3 intermediate blade region

14 central free region

16 shaft connecting part

17.1, . . . , 17.n borehole

18.1, 18.2, 18.3 rotor blade intermediate spaces

19.1, 19.2, 19.3 transition region

20 rotor

21 axis of rotation

22 axial direction

23 circumferential direction

24 first axial end face

25 second axial end face

26 axial terminus face

27.1, . . . , 27.n threaded boreholes

28 incident flow direction

29.1, 29.2,

29.3, 29.4 force components

30.1, 30.2, 30.3 shear forces

31 lateral opening

32 partition plane

33 angular offset

What is claimed is:
 1. A rotor assembly, comprising: a driveshaft havingan assigned axis of rotation which establishes an axial direction and acircumferential direction, said driveshaft including an axial terminusface; a rotor having a plurality of rotor blades each of which includesa profiled rotor blade section and a blade fastening section, each saidprofiled rotor blade section being configured for having an incidentflow in said axial direction, each said blade fastening sectionincluding a first contact region and a second contact region, said firstcontact region being at least indirectly supported on said bladefastening section of a first adjacent one of said plurality of rotorblades, said second contact region being at least indirectly supportedon said blade fastening section of a second adjacent one of saidplurality of rotor blades, each said blade fastening section includingan axial end face, each said blade fastening section being fastened atleast one of in a formfitting manner and by way of a screw connection onsaid driveshaft so that there is a connection between a respective oneof said plurality of rotor blades and said driveshaft on said axial endface of said blade fastening section, said axial end face being oppositeto said axial terminus face on said driveshaft in an installed position,each said plurality of rotor blades including a transition from saidprofiled rotor blade section to said blade fastening section, saidtransition having an external contour which is free of a plurality ofconstrictions, said rotor including a plurality of intermediate elementshaving an elastic intermediate layer, said plurality of intermediateelements being between a plurality of said blade fastening section ofadjacent ones of said plurality of rotor blades.
 2. The rotor assemblyaccording to claim 1, wherein said rotor includes a segmented hub part,one of (a) said plurality of blade fastening sections and (b) anentirety of said plurality of blade fastening sections and saidplurality of intermediate elements forming said segmented hub part ofsaid rotor.
 3. The rotor assembly according to claim 1, wherein saidfirst contact region and said second contact region are each detachablyconnected to said blade fastening section of an adjacent one of saidplurality of rotor blades and thereby form a plurality of detachableconnections which are implemented at least one of as a plurality ofscrew connections and as a plurality of formfitting connections.
 4. Therotor assembly according to claim 1, wherein said first contact regionand said second contact region of each said blade fastening section arerespectively arranged in an intermediate blade region of said rotor,said intermediate blade region having angular offset in saidcircumferential direction to a partition plane between adjacent ones ofsaid plurality of rotor blades which is at most ±30°.
 5. The rotorassembly according to claim 1, wherein said plurality of intermediateelements of said rotor are a plurality of separate intermediate elementswhich are arranged spatially partitioned and which produce a detachableconnection of adjacent ones of said plurality of blade fasteningsections.
 6. The rotor assembly according to claim 1, wherein, for eachof said plurality of rotor blades, an assigned said profiled rotor bladesection and an assigned said blade fastening section are materiallyjoined.
 7. The rotor assembly according to claim 1, wherein saidprofiled rotor blade section includes a first part and a second part,said first part of said profiled rotor blade section being formed by ablade stump, said blade stump being materially joined to each said bladefastening section, said second part of said profiled rotor blade sectionbeing detachably connected to said blade stump.
 8. The rotor assemblyaccording to claim 1, wherein said rotor includes a central free region,said plurality of blade fastening sections enclosing said central freeregion of said rotor.
 9. The rotor assembly according to claim 8,wherein a contour of said central free region in a rotor plane deviatesfrom a circular contour.